This type of electrically-driven compressor is disclosed in, for example, patent document 1. In the electrically-driven compressor disclosed in patent document 1, a scroll type compression mechanism and a motor (electric motor) for driving the compression mechanism are accommodated in a casing (housing) that forms the outer shell of the electrically-driven compressor. The motor, which is operated by the control an inverter controller, drives the compression mechanism. A tubular wall having a tubular shape projects from the upper part of the casing, and a cover member is fastened by bolts to an open end of the tubular wall with a circuit board of the inverter controller (motor drive circuit) located therebetween.
The cover member is attached so as to cover the inverter controller and protect the inverter controller from dust and moisture. A seal member (sealing member) is arranged at the open end of the tubular wall. The pressure condition in the casing is ensured by arranging the seal member (sealing member) between the tubular wall and the circuit board. A seal member is further arranged at an open end of the cover member. Dust and moisture are prevented from entering the cover member by arranging the seal member between the cover member and the circuit board.
In patent document 1, a rubber 0-ring is used as the seal member. The seal member must be arranged along the entire circumference of the open end of the tubular wall and be in close contact with the open end of the tubular wall and the circuit board in order to ensure the pressure condition in the casing. The additional seal member must be arranged along the entire circumference of the open end of the cover member and be in close contact with the open end of the cover member and the circuit board to prevent dust and moisture from entering the cover member. In order to arrange each seal member along the entire circumference the corresponding open end, the shape of the seal member must be sustained to conform to the shape of the corresponding open end. Thus, a groove for sustaining the shape of the seal member must be formed at each open end in patent document 1.
A gasket may be used as the seal member. Since a gasket formed from a metal plate, a means for sustaining the shape of the seal member is not required. When the gasket is employed in the electrically-driven patent document 1, a gasket is held in close contact with the open end of the tubular wall and the circuit board to ensure the pressure conditions in the casing. An additional gasket is held in close contact with the open end of the cover member and the circuit board to prevent dust and moisture from entering the cover member.
The inverter controller employs a structure in which electrical components connected to the circuit board come into contact with the cover member so as to radiate heat from the electrical components through the cover member. This improves the heat radiation of the heat generated by the electrical components. However, when the electrical, components contact the cover member, a gap is formed between the open end of the cover member and the circuit board. A gasket has the shape of a thin plate. Thus, when a gasket is used, the cover member must be accurately manufactured to equalize the gap between the open end of the cover member and the circuit board with the thickness of the gasket in order to close the gap so that the cover member comes into close contact with the gasket. If the cover member is manufactured with low accuracy, the adhesion of the open end of the cover member to the gasket decreases, and dust and moisture enters the cover member from the space between the cover member and the circuit board.
[Patent Document 1] Japanese Laid-Open Patent Publication No. 2002-364536